Eurostar said it has formed a partnership with Thalys to offer through-ticketing and common fares for journeys between London, Brussels, Amsterdam and Cologne.

The two groups also plan to improve connections and co-ordinate timetable information at rail hubs such as Brussels-Midi.

Eurostar said the alliance with Thalys, which runs 186mph trains between Paris, Brussels and Cologne, may be extended to other high speed operators.

It is the first phase of the so-called RailTeam initiative, under which the European railways plan to work together to beat off competition from airlines.

Chief executive of Thalys International, Jean-Michel Dancoisne, said: 'This partnership can be extended progressively in Europe with other high-speed rail operators, bringing greater benefits for our customers.'

The agreement follows the success of an initiative launched in April to offer a ticket for London-Cologne via Brussels in partnership with German state railway Deutsche Bahn (DB).

Traffic increased by 75 pct in August owing to 'the use of aggressive pricing compared with the leisure ticket price from airlines', said Dancoisne.

After Paris, Amsterdam is the second most popular destination for Eurostar passengers from London and Eurostar believes it could take a 20 pct share of the market within two years.

Eurostar eventually plans to launch a direct London-Amsterdam service, although it is unlikely to happen for at least three to four years due to technical issues, a Eurostar spokesman said.

French state railway SNCF, Belgian state rail operator SNCB and the Eurostar UK Ltd consortium run Eurostar, which runs services between London, Paris and Brussels. Eurostar UK Ltd consists of National Express Group PLC, SNCF, SNCB and British Airways PLC. Thalys is run by SNCF, SNCB, Dutch state railway NS and DB.